I use Sweet PDZ in my goat barn. It has a dirt floor, with straw or old hay for bedding. DH scoops up poop in the mornings, and we use it in the garden for composting. You should see the tomatoes I grew this year.
The Sweet PDZ is great on the urine spots. The urine is what you get the most offensive odor from, not the nannie berries.
I use an old screen wire kitchen strainer. I keep the bag in the corner of the milk room, and as I go inside the barn area scoop some up and sprinkle it around. I love the stuff. It really works well.
Now in winter time when they hang around inside the barn it's more of a challenge to keep it smelling sweet, but I do work at it. They say if you can smell "ammonia" smell it's bad for the animals.
The big thing you need in a barn is VENTILATION. We have roof vents, vents under the eves, vents in the walls and windows with "hardware cloth" over them. In summer I keep a big commercial fan going to move the air around.
Different folks use different things for barn floors, depending on the area you are in. I would like to try putting a layer of sand over a loafing area to see if it would hold down the smell. I may do that in one area of the barn when we clean it out this year in late fall.
DonnaBelle